Over the last two decades a variety of stereoscopic and autostereoscopic display systems have been developed. These systems aim to provide the viewer with a three-dimensional (3D) impression of still and/or motion video images. In general (auto)stereoscopic devices aim to provide the respective left and right eye of a viewer with an appropriate left and right image which when interpreted by the human visual system of the viewer result in a 3D impression.
Stereoscopic display systems comprise active glasses-based systems such as those using shutter glasses. In shutter glasses based systems a display device generally displays left and right images in a time-multiplexed manner. The shutter glasses in turn are operated in synchronization with the display system to allow for the respective left and right images to reach the corresponding eye of the viewer. Other glasses-based systems are passive, such as the polarization glasses used in 3D cinema.
Although the above stereoscopic systems provide what is generally accepted to be a convincing 3D experience, users tend to find the need for special glasses a nuisance. As a result autostereoscopic systems have been developed wherein two or more views are presented simultaneously on the display device. In addition such display systems are fitted with light directing means, such as barriers, or lenticulars, which direct the respective views into different viewing directions. For example, U.S. Pat. No. 6,064,424 presents an example of a lenticular-based autostereoscopic display system.
When a viewer looks at the autostereoscopic display device, he will generally receive two distinct views; one for his left eye and one for his right eye. These images in turn are combined by the human visual system into a 3D impression.
In order for stereoscopic and autostereoscopic devices to provide a high quality 3D impression, it is normal to provide a video signal comprising more than a conventional 2D image. A wide variety of alternatives has already been disclosed. Stereoscopic display devices generally require content to be delivered in a form comprising left and right images in a time-sequential and/or multiplexed manner.
Autostereoscopic displays on the other hand generally require more than two views. For this reason certain display devices require multiple views in a time-sequential and/or multiplexed manner. International Patent Application WO2006/137000 provides an example of another method to encode three-dimensional video data. This particular method of exchange of image data allows the exchange of a conventional 2D image, a corresponding depth image (indicative of the distance of pixels in the viewing direction), and occlusion information. Such information can be used to render one or more views of the image, using techniques such as disclosed in “Layered Depth Images”, by J. Shade, et al, ACM SIGGRAPH'98, pp. 231-242.